: Rear leveling



Jneedom14
07-01-13, 12:17 PM
Now i don't even hear the compressor on start-up with a lot of objects in the trunk? Compressor or the sensors the shocks are good no leaks what could it be? Where are the sensors located? does it look like its sagging a lot remind you im on a slight incline121834

Guy.Seminerio
07-01-13, 12:27 PM
Is it just me or is the front high??

Jneedom14
07-01-13, 12:38 PM
or is the back low im wondering what i need to buy cause my shocks in the rear are good. I think its the compressor and sensors.

Guy.Seminerio
07-01-13, 01:11 PM
Rear is definitely low. No doubt there. But the front seems high.
http://www.thecarconnection.com/photos/cadillac_sts_2007#&ui-state=dialog

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If you hear the compressor working its the bags leaking. That's my understanding.

mckellyb
07-01-13, 06:37 PM
The compressor is exceptionally quiet, however, yeah, that looks low to me.

EChas3
07-02-13, 01:05 AM
Specifics... The STS has two leveling systems. Do you have RPO FE1 or FE3 w' MRC?

Ludacrisvp
07-02-13, 12:39 PM
Specifics... The STS has two leveling systems. Do you have RPO FE1 or FE3 w' MRC?
I would venture a guess at FE1 just based on the OEM rims that are equipped.

STS-4000
07-02-13, 08:49 PM
Mine sits low in the rear too and my RPO code is FE3 with magride. Is this normal for it to sit that low in the rear? (sorry for hijacking your thread)

122210

1BadCadSTS
07-02-13, 09:19 PM
Measure it.

Ludacrisvp
07-02-13, 09:25 PM
Mine sits low in the rear too and my RPO code is FE3 with magride. Is this normal for it to sit that low in the rear? (sorry for hijacking your thread)

122210

Looks a bit low to me. But measure it before you change anything.

B1n2fra
07-03-13, 01:38 AM
Specifics... The STS has two leveling systems. Do you have RPO FE1 or FE3 w' MRC?

What other leveling system besides the air shocks does it have?

STS-4000
07-03-13, 12:37 PM
Alright I'm gonna stop by wal-mart later to pick up a tape measure and I'll get back to you guys with the measurements

Submariner409
07-03-13, 12:43 PM
MRC is a suspension control system, no leveling involved.

ALC/ELC uses rear shocks with auxiliary air bladders, height sensor(s) and a controlled compressor to compensate for extra weight in the trunk or rear seat. It is NOT "air ride".

Google "lord delphi magnetic ride control system".

dkozloski
07-03-13, 01:07 PM
Mine sits low in the rear too and my RPO code is FE3 with magride. Is this normal for it to sit that low in the rear? (sorry for hijacking your thread)

122210It looks normal to me.

curtc
07-03-13, 01:37 PM
What other leveling system besides the air shocks does it have?

If not equipped with MRC the rear leveling is done by the shock itself rather than an air compressor...Google "Nivomat" to find out how they work.

Ludacrisvp
07-03-13, 08:42 PM
I just measured my car that has been off for 24+ hours and has FE3 w/ MRC.
Front = 28.5"
Rear = 28.25"
Tank full, empty trunk


And since my Monte Carlo was next to it... (it has FE3 as well :) )
Front = 28.25"
Rear = 28.0"
Tank 1/2 full w/ two 12" subs in 2 boxes.

EChas3
07-04-13, 12:45 AM
All sounds within normal range. I posted the two in my garage a few days back. I think the AWD 1SG was about 1/2" lower in back than the 1SE Hertz.

STS-4000
07-04-13, 04:17 PM
I just measured my car that has been off for 24+ hours and has FE3 w/ MRC.
Front = 28.5"
Rear = 28.25"
Tank full, empty trunk


And since my Monte Carlo was next to it... (it has FE3 as well :) )
Front = 28.25"
Rear = 28.0"
Tank 1/2 full w/ two 12" subs in 2 boxes.


Sorry this may be a stupid question, but how are you measuring it? Are you measuring from the ground up to the fender?

Ludacrisvp
07-04-13, 04:28 PM
Sorry this may be a stupid question, but how are you measuring it? Are you measuring from the ground up to the fender?
Correct, from the ground to the highest point on the fender (top of the arch).
Both cars parked in the garage on cement floor.
Wasn't sure of where else to use as measurement points.

STS-4000
07-04-13, 05:03 PM
Correct, from the ground to the highest point on the fender (top of the arch).
Both cars parked in the garage on cement floor.
Wasn't sure of where else to use as measurement points.

Ah okay I thought so. I bought a tape measure on my way to work yesterday and i wasn't sure how to measure it, but now I know.

Thanks.

STS-4000
07-04-13, 07:22 PM
Alright so I measured my ride height and this is what I got.

Front=28.75"
Rear=27.5"

And these measurements were made after letting the car idle for about 5 minutes.

EChas3
07-05-13, 12:27 AM
4000- My AWD is half an inch lower in back than front. I think yours is high in front and low in back. Are you on stock suspension, wheels & tires?

Ludacrisvp
07-05-13, 03:04 AM
I agree with E ...
what are the tire sizes on front and rear?
anything in the trunk?
has anyone replaced any suspension components?
proper tire pressure?

STS-4000
07-05-13, 11:11 AM
Front 235/50-18
Rear 255/45-18

I removed my 80lb toolbox out of the truck before measuring it and as for as I know the suspension is stock.

EChas3
07-05-13, 08:53 PM
Try driving it around for a while with an empty trunk and then measuring. I think there's a leveling problem.

STS-4000
07-05-13, 10:10 PM
Alright tomorrow I'm gonna empty my trunk out and drive it around and measure it afterwards.
Oh btw, sometimes I can hear the air compressor turn on for about 2 seconds and then turn off and the car's ride height won't budge.

Submariner409
07-05-13, 10:17 PM
I hate to say this, but floor-to-fenderwell measurements have absolutely NOTHING to do with ride height measurements. Two different tires or even different tire inflation pressures (on different cars) can throw that measurement off by as much as 0.5" or more.

Suspension heights are measured using a specific set of specs from the service manuals - it's related to the geometry of the lower suspension arms, and there is a specific set of loads that are used when doing the measurements.

ELC compressors (systems) do a prove-out shortly after Key:ON - you'll never see a height change during that sequence.

Turn the Key:ON and let the ERC do its preload. Pop the trunk - 3 of you hop onto the open trunk lip. ELC should level the rear. All hop off - you should hear air escaping in the RR wheelwell as the system again levels the rear.

B1n2fra
07-06-13, 06:48 PM
If not equipped with MRC the rear leveling is done by the shock itself rather than an air compressor...Google "Nivomat" to find out how they work.

I know how nivomats work. I though they were only available on the cts. Can I get nivomat shock and replace my air shocks with these

1BadCadSTS
07-06-13, 07:44 PM
Yes but you must bypass the Magride sensor or you'll get suspension messages and be speed limited to 80 mph.

mckellyb
07-07-13, 10:09 AM
Submariner409 nailed it.

The only time I've heard my compressor, and I was listening for it, was when I put 12 cubic feet of mulch in the trunk (in bags) with another two 40 lb. bags of fertilizer stuffed in there.

Even then, it was very quiet.

EChas3
07-07-13, 03:42 PM
I agree. The only time I heard mine was a bit before it failed; over-running due to that approaching failure. I was bending over, putting a walker in the trunk for a passenger. It's not at all like my old Roadmaster that growled!

STS-4000
07-09-13, 10:36 PM
Well I drove around with pretty much an empty trunk and the rear of my car is still sitting low. I did sit in the trunk and I heard the compressor turn on and the car lifted about a quarter of an inch, but it's still sitting 27.5 in the rear.